A153464 Numbers k such that 4*k+9 is not prime.

0, 3, 4, 6, 9, 10, 12, 14, 15, 17, 18, 19, 21, 24, 27, 28, 29, 30, 31, 33, 34, 36, 38, 39, 40, 42, 44, 45, 48, 49, 50, 51, 52, 53, 54, 57, 59, 60, 61, 63, 64, 66, 69, 70, 72, 73, 74, 75, 78, 79, 80, 81, 83, 84, 87, 88, 89, 90, 92, 93, 94, 96, 99, 101, 102, 104, 105

Offset

1,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Example

Distribution of the terms in the following triangular array:
  0;
  *,4;
  3,*,10;
  *,9,*,18;
  6,*,17,*,28;
  *,14,*,27,*,40;
  9,*,24,*,39,*,54;
  *,19,*,36,*,53,*,70;
  12,*,31,*,50,*,69,*,88;
  *,24,*,45,*,66,*,87,*,108;
  15,*,38,*,61,*,84,*,107,*,130; etc.
where * marks the non-integer values of (2*h*k + k + h - 4)/2 with h >= k >= 1. - Vincenzo Librandi, Jan 14 2013

Mathematica

Select[Range[0, 200], !PrimeQ[4 # + 9] &] (* Vincenzo Librandi, Jan 14 2013 *)

Prog

(Magma) [n: n in [0..150] | not IsPrime(4*n+9)]; // Vincenzo Librandi, Jan 14 2013

Crossrefs

Cf. A111199.

Sequence in context: A080336 A082692 A032706 * A288463 A189297 A350977

Adjacent sequences: A153461 A153462 A153463 * A153465 A153466 A153467

Keyword

nonn,easy

Author

Vincenzo Librandi, Dec 27 2008

Extensions

79 added by R. J. Mathar, Sep 23 2009

0 added by Arkadiusz Wesolowski, Aug 03 2011

Status

approved